For example, the first threshold is a maximum value of a quantity of frequency resources to be selected and monitored that is configured by the network device for the terminal, and may be a value that is less than or equal to M. The third threshold is a maximum value of a quantity of target first frequency resources to be selected that is configured by the network device for the terminal, and is less than or equal to Y.

For example, the network device may configure, for the terminal by sending configuration information to the terminal, the second threshold corresponding to the M first frequency resources, and the maximum value of the quantity of the frequency resources to be selected and monitored. The configuration information may be sent to the terminal by using one of the following messages: a Physical Downlink Control Channel (PDCCH) and Radio Resource Control (RRC) signaling.

For example, if one first frequency resource is selected as the target first frequency resource, the second predetermined rule includes any one of the following: a free first frequency resource is selected randomly, a first frequency resource with best channel quality (such as best Reference Signal Received Power (RSRP)) in the Y first frequency resources is selected, and a first frequency resource satisfying the first condition is selected randomly. If the Y first frequency resources include a plurality of first frequency resources with best channel quality, the terminal needs to select a first frequency resource randomly from the plurality of first frequency resources with best channel quality; or if the Y first frequency resources include a plurality of first frequency resources satisfying the first condition, the terminal needs to select a first frequency resource with best channel quality from the plurality of first frequency resources.